NOAO >   Observing Info >   Approved Programs >   2002A-0358

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Proposal Information for 2002A-0358


PI: Mukremin Kilic, The University of Texas at Austin, kilic@bullwinkle.as.utexas.edu
Address: 2511 Speedway RLM 15.308, Austin, TX 78712, USA

CoI: Don E. Winget, U. Texas, McDonald Obs.
CoI: Ted von Hippel, U. Texas, McDonald Obs.
CoI: Chuck F. Claver, Kitt Peak, NOAO

Title: Identification of Cool White Dwarfs in the NOAO Deep Wide-Field Survey

Abstract: We propose a search for the cool white dwarfs belonging to the Galactic disk by extending the NOAO deep wide-field survey. Our search will identify an enormous number of new white dwarfs which will improve the white dwarf luminosity function (WDLF) by an order of magnitude in the range of log(L/L_\sun)~-3.2 through log(L/L_\sun)~- 4.2. This will provide unprecedented leverage in determining the true age of the oldest white dwarfs by constraining the physics (\it e.g., phase separation, crystallization and convective efficiency) that dictate the cooling rates. In addition this will also provide an important constraint in the star formation history of the Galaxy from 1.0 - 7.0 Gyrs. The broadband filter data obtained in the NOAO Deep- Wide survey provides the majority of our requirements- the high quality B_WRI photometry and background galaxy rejection to V=23. Here, we request time with the narrow band DDO-51 filter to separate cool white dwarfs from other stellar types of similar T_e. We propose to obtain DDO-51 photometry of the northern survey field to complement the NOAO Deep-wide data and identify the population of cool white dwarf stars including hundreds of the oldest, and faintest ones. These data, along with follow-up spectroscopy with HET and/or Gemini GMOS, will ultimately resolve the controversies of the shape of the WDLF which we will use to constrain the interior physics of cooling WDs and place WD cosmochronometry on a firmer foundation.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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